Its equivariant Borel-Moore homology
\(H_*^T(^{\gamma ,+}_)\)  is bigraded by the connected component \(t^i\in \pi _0(_^+)=\)  and the (half of the) cohomological grading \(q^j\in \)  and carries two bigraded \(S_n\) -actions, one from the Springer action and one from the monodromy as \(s\)  moves in a family. In [1]}, these are called the star and the dot actions, respectively. In [2]}, they are called the Springer action and the equivariant centralizer-monodromy actions, respectively.
